Escapement mechanism for typewriting machines



July 3, 1934. I TREGQ 1,964,750

ESCAPEMEINT MECHANISM FOR TYPEWRITING MACHINES Original Filed Aug. 9} 1929- 2 Sheets-Sheet 1 I INVENT OR Fran/r H 7/1940. B Y

July 3,1934. F. H. TRE Q 1,964,150

ESCAPEMENTMEQHANISM FOR TYPEWRITING MACHINES OriginalFiled Aug..9. 1929 2 Sheets-Sheet 2 INVENTOR fiwn/r H Trego.

% ATTORNEY Patented .iui 3, i934 genie Frank H. 'lrego, New York, N. HQ, asaignor, by

mesne assi a: ents, to Ralph f3. flonhead Corporation, New York, N. ii'., a corporation of Delaware @riginal application August 9, 1929, Serial No.

389,603. Divided and this application Decemher l, 1932, Serial No. 6%,272

l9 Claims.

This invention relatesto typewriting machines and more particularly to escapement mechanism therefor. It is a division of my application No. 384,603, filed Aug. 9, 1929. v

A feature of the invention relates to the construction and the manner of mounting the escapement mechanism.

Other features and advantages will hereinafter appear.

In the drawings:

Fig. 1 is a longitudinal, vertical section, of a portion of the machine, taken near the middle thereof;

Fig. 2 is arear view of a portion of the machine;

Fig. 3 is a sectional side view showing the pinion element, escapement wheel and associated parts including the carriage release mechanism, on the escapement shaft;

Fig. 4 is a sectional rear view taken on the line 4-4 of Fig. 2; and v Fig. 5 is a detail end view of ried by the escapement shaft.

Similar characters refer to similar parts throughout the several views.

the pawl car- The invention is shown applied to a machine known as the Varityper and includes a main frame 29 to which is secured a track 21 upon which a carriage 22 is mounted to travel back and forth transversely of the machine. The carriage is provided with a bar 23 which co-operates with the track 21 through anti-friction rollers or balls 24 to guide said carriage. The carriage is further guided by a bar 25 at its upper end co-operating with rollers 27. mounted on the main frame 20.

The carriage is urged in a letter feed direction by a carriage propelling means or spring drum, not shownpconnected to the carriage by a strap or draw band 32...,iLetter feed movements of the carriage are effected upon the actuation of character keys, not shown, and these movements are controlled by escapement mech- 'anism, indicated generally by the numeral 33.

/ The escapement mechanism includes a pinion element 3.4 having a sleeve'35 slidably supported on a shaft 36 supported in a rear cross-bar 3'1 9 of the main frame and 8. lug 38 of said frame.

The sleeve has secured thereto three pinions 39,40 and 41 of different diameters to effect variable spacing of the carriage in a'manner described in my application No. 361,899. filed May 10, 1929, now Pat. No. 1,918,299, dated July 18,

1933. Any one of the pinions may be engaged.-

(CH. Milt-4L9) by a'rack 42 carried by arms 43, 63* pivotally supported on studs 44, on carriage ends 45.

The sleeve 35 has further secured thereto an internal "ratchet 46 by means of screws 66 the ratchet engaging a pawl'l having a shank 48 en- 0 gaging in a hole 49 of an enlarged portion 56 oi. the shaft 36. A. spring 51, held between the end of the shank and a plug 52, normally holds the pawl in engagement with the teeth of the ratchet is. The head 53; of the pawl 47 is flat and elongated and engages in a slot 54 formed in the enlarged portion 59 of the escapement shaft to keep it from turning. The sleeve 35 is slidable lengthwise of the shaft 36 while setting it for the various feeds and because of the length of the'pawl head 53 the ratchet 46 engages it in all positions of the sleeve. An escapement wheel 56 is rigidly connected to the shaft 36 by a pin 57 engaging in an aperture 58 in the escapement wheel and in an aperture 59 in the enlarged portion of said shaft. It is held against an end face of the enlarged'portion 50 by a nut element 60 screwed on a threaded portion 61 of the shaft 36.

From the foregoing it will be understood that 30 the carriage is under the influence of the spring drum which tends to rotate the escapement shaft 36 through the medium of the feed rack 42, pinion element 34, ratchet 46 and pawl 47. The escapement wheel'is'normally held against rotation, however, by a loose dog 62 pivoted on a stud 63 of a frame including two arms 64 and 65; said frame being pivotally supported on the escapement shaft 36. The arm 65 has an extension 67 engaging a stop 68 against which said extension is normally 90 H held by the action of the escapement wheel on the dog 62.

The rear end of an arm '70, upon a depression of the type keys and the space bar, is moved downwardly to actuate an inwardlylprojecting arm 71' to rock an escapement lever or dog rocker 72 about a pivot stud '73 against the action of a spring 74. Said lever is provided with a slot 75 into which projects a pin '76 from the dog 62 so that as the lever '72 is actuated the dog 62 is swung. out of en- 10o gagement with the escapement wheel 56. A fixed dog 7''! secured to the lever or dog rocker '12 is brought into the path of the teeth of said escape-- F ment wheel before the release of said wheel from the dog 62 is effected. The loose dog 62 is then carried upwardly, past the previously engaged tooth of the escapement wheel. This upward movement of the loose dog is effected by a spring, not shown, connected to the printing hammer 78 which is connected to the frame 64 by a stud 78 carried by the said frame and extending freely into an aperture in the printing hammer. Upon release of the depressed key the arm 70 is returned to normal thus permitting the dog rocker 72 to return to normal. The loose dog 62 is .thus swung back, by the dog rocker 72, into the path of the next succeeding tooth of the escapement wheel, and the fixed dog 77 is carried out of engagement withthe escapement wheel thus permitting the completion of a letter space movement of the carriage.

To hold the escapement shaft 36 on its bearings, or in other words, prevent accidental rearward movement of said shaft, there is provided a platelike element 79 which may be secured to the stud 73 by a screw 79 and is provided with an end 79 extending into a groove 79 formed by the nut 60 and the escapement wheel. This element 79 also facilitates removal of the escapement shaft from the frame. For example, if the bracket 123 is first loosened and the plate 79 is then removed the escapement shaft with the pawl carrying frame thereon may be detached from the machine by pulling it out at the back of the machine, the stud 78 moving readily out of the aperture in the printing hammer.

The pinions 39, 40 and 41 vary in increasing diameters and they are of the same pitch as the rack 42. They also vary respectively in size ac.- cording to the number of teeth. Accordingly, for each movement of the escapement wheel, which is constant, the angular distance of actuation of the pinions is the same, but the linear distances which the rack may be fed by the various pinions increase as the diameters of the pinions increase.

To shift the sleeve 35 to select any one of the pinions there is provided means including a shift lever 85 pivotally su ported on the main frame 20. The inner end 0 1 the lever 85 is bifurcated and has two studs 87 projecting into an annular groove 88 formed in the periphery of a flange 89 of the sleeve 35. Thus, due to engage-' ment of the studs 87 in the groove 88, the sleeve may be slid back and forth relatively to the rack 42, to the desired position, on the escapement active' pinion. After the pinion corresponding with the desired letter spacing has been shifted into co-operative relation with the rack 42, the latter is lowered into engagement therewith.

To release the carriage from the escapement there are provided two release levers 110, one on eachcarria'ge end 45, and both supported onand at opposite ends of a shaft 112. Each release lever is actuable by a finger piece 113 against the action of a suitable return spring, not shown. The lower end of each release lever has a slot 116 (Fig. 1) into which projects a pin 117 from an arm 118 pivotally supported on an offset of the hub 96 on the ,rack supporting arm 43. The arms118 have each an ear 120 bent therefrom to which a bar 121, extending lengthwise of the carriageis secured. Said bar is swung in a counter clockwise direction (Fig. 1) upon the actuation'of either release lever 110 and causes the bar 121 to engage the end of an element or arm 122 of intermediate mechanism indicated generally by the numeral 123 connecting the bar 121 with-a pawl actuating plunger 105 of the escapement mechanism. The arm:122 is located near the middle of the machine so that it may always be engaged by the bar 121 in any position of the carriage. It is secured to a sleeve 124 fixed to a shaft 125 supported in cars 126 and 126 of a bracket 127 secured to the machine frame by screws 128 and .129. When actuated, the arm 122, moves against the action of a return spring 130 coiled about the shaft 125, one end of which is connected to the said shaft by a screw 131 threaded' through a collar 132 on the shaft 125 and bearing against the latter; the other end of the spring being connected to a lever 133. The other end of the sleeve 124 has secured thereto an arm 134 which extends upwardly and rearwardly behind the escapement wheel 56. The upper end of the arm 134 has a slot 135 through which extends a stud 136 in a head 137 threaded on the end of the thrust rod 105 so that upon the actuation of the arm 134 the thrust rod is moved inwardly to cause a cam end 107 to engage a cam surface 108 of the pawl 47 to move said pawl out of engagement with the ratchet 46 to release the carriage.

The cam end 107 of the thrust rod 105 may be adjusted relatively tothe inclined surface 108 of the pawl by screwing the thrust rod more or less into the head 137. It may then be locked in its adjusted position, with respect to the head 137, by a nut 138 also threaded on the rod 105.

While certain preferred embodiments of the invention have been shown and described, it will be understood that changes in form, arrangement, proportions, sizes and details thereof may be made without departing from the scope of the invention as defined in the appended claims.

I claim:-

1. In a typewriting machine, the combination of a main frame, a carriage, a rack on said carriage, an escapement shaft, means to support the shaft on the main frame, a pinion on said shaft and engaged by said rack, an escapement wheel secured to said shaft and located to one side of the support, and detachable means on the main frame to engage the opposite side of the escapement wheel to hold the shaft against axial displacement on the supporting means.

2. In a typewriting machine, the combination of a main frame, a carriage, a rack on said carriage, an escapement shaft, means to support the shaft on the main frame, a pinion on said shaft and engaged by said rack, an escapement wheel on said shaft, a nut to assist in securing the escapement wheel to said shaft, there being an annular groove between the escapement wheel and said nut, and a detachable element secured to the main frame and engaging in said groove to prevent axial displacement of the shaft on its supporting means.

3. In a typewriting machine, the combination of a main frame, a carriage on said main frame, a rack on said carriage, an escapement shaft, means to support the shaft on said main frame, a pinion on said shaft and engaged by said rack, an escapement wheel secured to said shaft and located to one side of the support, means at the opposite side of the escapement wheel to form therewith an annular groove extending around the escapement shaft, and means on the main frameto engage in said groove to hold the shaft against axial displacement on the supporting means.

4. In a typewriting machine, the combination of a main frame, a carriage, a rack on said carriage, an escapement shaft, means to support the shaft on the main frame, a pinion on said shaft and engaged by said rack, a shoulder on said shaft, an escapement wheel on said shaft, means to prevent rotation of the escapement wheel on said shaft, a nut to hold the escapement wheel against the shoulder of said shaft, there being an annular groove between the escapement wheel and said nut, and means on the main frame to engage in said groove to prevent axial displacement of the shaft on its supporting means.

5. In a typewriting machine, the combination of a carriage, a rack thereon, a pinion engaged by said rack, a shaft to support said pinion, an enlarged portion on said shaft, an escapement wheel on said shaft and engaging one face of said enlarged portion, a ratchet on said pinion, a pawl on said enlarged portion to engage said ratchet, means to locate the escapement wheel circumferentially of the shaft with respect to the pawl and to prevent rotation of the escapement wheel on said shaft, and means on said shaft to hold the escapement wheel against the "face of the enlarged portion.

6. In a typewriting machine, the combination of a carriage, a rack thereon, a pinion engaged by said rack, a shaft to support said pinion, an enlarged portion on said shaft, an escapement wheel on said shaft and engaging one face of said enlarged portion, a ratchet on said pinion, a pawl on said enlarged portion to engage said ratchet, a dowel pin to locate the escapement wheel circumferentially of the shaft with respect to the pawl and to prevent rotation of the escapement wheel on said shaft, and a nut threaded on said shaft to hold the escapement wheel against the enlarged portion of said shaft.

7. In a typewriting machine, the combination of a carriage, a rack thereon, a shaft including a head between its ends, a pinion on said shaft at one end of the head, a one way driving connection between the pinion and the shaft, an escapement wheel on said shaft and at the opposite end of said head, a dog to engage the escapement wheel, a carryingframe for said dog, said frame including two parallel arms, one arm being supported on said head and located at the front of the escapement wheel, the other arm being supported on that portion of the shaft which supports the escapement wheel and located behind the escapement wheel, means toprevent rotation of the escapement wheel on said shaft, and a nut thread/- ed on said shaft and located between the last mentioned arm and the escapement wheel to hold the latter against said head.

8. In a typewriting .machine, the combination of a carriage, a rack thereon, escapement mechanism including a pinion engaged by'said rack, a shaft to support the pinion, an enlarged portion on said shaft,an escapement wheel on said shaft, a nut threaded on said shaft to hold the escapement wheel against the enlarged portion, means connecting the escapement wheel' with said enlarged portion, two bearing-brackets for said shaft one embracing the enlarged portion of said shaft,

the other engaging the forward end of the shaft, both of said brackets being located to one side of the escapement wheel, and means engaging the other side of the escapement wheel to hold said shaft on its bearing brackets.

9. In a typewriting machine, the combination of a carriage, a rack thereon, escapement mechanism including a pinion engaged by said rack, a shaft to support the pinion, an enlarged portion on said shaft, an escapement wheel on saidshaft, means to hold the escapement wheel against the enlarged portion, means to prevent rotation of the escapement wheel on said shaft, supporting means for said shaft located in front of the escapement wheel, and detachable means engaging the rear of the escapement wheel to hold said shaft against axial movement on its supporting means. I

10. In' a typewriting machine, the combination of a carriage, an escapement shaft including a head and reduced portions at opposite ends, a pinion element rotatably supported on one of the reduced portions of said shaft, an enlarged hollow portion on the pinion element into which the head extends, an internal ratchet on the enlarged portion of the pinion element, an escapement wheel supported on the other reduced portion of the shaft, a pin extending through the escapement wheel into the head of the escapement shaft, said shaft having a radial aperture and an axial bore extending thereinto and a slot on its periphery, a pawl to engage said ratchet, and a spring for said pawl, said pawl having a flat head to engage in said slot and a shank to engage in said aperture.

FRANK H. TREGO. 

